THURSDAY, March 28 (HealthDay News) -- Poor children who move three or more times before they're 5 years old are at increased risk for behavioral problems, a new study contends.

Researchers examined data from about 2,800 children born in 20 large U.S. cities between 1998 and 2000. By age 5, fewer than one-quarter of the children had never moved, 48 percent had moved once or twice, and 29 percent had moved three or more times.

Among the children who moved three or more times, 44 percent were poor. These children had more attention problems, anxiety or depression, and aggressiveness and hyperactivity at age 5 than those who had moved fewer times or never moved.

The increases in behavioral problems were seen only among poor children who moved three or more times. This suggests that frequent moves early in life are most disruptive for poor children, according to the authors of the study, published March 28 in the journal Child Development.

"The United States is still recovering from the great recession, which has taken a major toll on the housing market," study leader Kathleen Ziol-Guest, a postdoctoral associate at Cornell University, said in a news release from the Society for Research in Child Development. "As housing markets have collapsed across communities, highly mobile low-income families have moved in search of work and less expensive housing."

She said the study findings suggest that the upheaval caused by the housing crisis likely will have negative effects on young children, especially poor children.

Previous research has shown that frequent moves are associated with a range of behavioral, emotional and school problems for teens.

Moving is fairly common in the United States, the researchers noted. For example, in 2002, nearly 7 percent of all children had been living in their current home for less than six months. That figure was 10 percent among poor children.

Although the study found an association between behavioral problems among poor children at age 5 and frequent moves before that age, it did not prove a cause-and-effect relationship.